1. David Cameron's chief of staff, Ed Llewellyn, turned down the opportunity for the prime minister to be briefed on the fact that Neil Wallis was giving PR advice to the Metropolitan police, according to the force. The outgoing Met commissioner Sir Paul Stephenson first alluded to an unnamed "No 10 official" who briefed the force that Cameron should not be "compromised" over the issue. The outgoing assistant commissioner John Yates subsequently named the official as Llewellyn.

2. The buck does not always stop at the top in the Met. Stephenson deflected a number of tough questions by telling MPs this was a matter for Yates, giving evidence later.

3. No one properly checked Wallis before he began work for Scotland Yard. The force's head of PR, Dick Fedorcio, told MPs that "due diligence" was carried out by Yates, even though Yates and Wallis were friends. Not so, said Yates: all he did was make a single phone call to Wallis to ask whether anything he had done could "embarrass" the force.

4. Stephenson resigned despite, he believed, still having the full support of Theresa May, the home secretary, London's mayor, Boris Johnson, and the bulk of the force. He told MPs: "It was against the advice of many, many colleagues – and, indeed, my wife." He added: "I'm not leaving because I was pushed or threatened."

5. Yates passed on the CV of Wallis's daughter within the force, thus possibly assisting her to get a job with the Met. He insisted he had done nothing wrong but "simply acted as a postbox".

6. The Metropolitan police has 45 press officers, 10 of whom previously worked for News International, figures revealed by Fedorcio.

7. Corporate PR consultancy can be a lucrative business. The Met received three tenders for a two-day-a-month contract to advise senior officers on press matters. The winning bid and "by far the cheapest", came from Wallis's company, at £1,000 a day.

8. Stephenson is not a fan of ex-colleague Andy Hayman's new career as a journalist. Asked whether he reads Hayman's Times column, the response was: "No, I do not."

9. Stephenson was determined to go out with a bang. He began quoting (inexactly) Macbeth on his resignation – "If it's done then best it's done quickly" – before vehemently defending his £12,000 free stay at Champneys health spa. He signed off with a clearly pre-prepared statement of defiance, describing his resignation as "an act of leadership".

10. We are living in strange times: there have been very few previous select committee hearings at which a Conservative MP (Mark Reckless) and a commissioner of the Metropolitan police go out of their way to praise the Guardian.

• This article was amended on 20 July 2011. In item six of the original, figures on police PRs were attributed to Paul Stephenson. This has been corrected.